A hook in its most basic form consists of the eye, shank, point, barb and gape. The “eye” of the hook is the ring or spade end of the hook where the leader or line is fastened. In some hooks, it can be fashioned as a knob. Running from the eye towards the bend of the hook is the “shank” while the sharp end that penetrates the fish’s mouth is called the “point”. The sharp point extruding from the back of the hook’s point is called the “barb” and functions to prevent a hooked fish from unhooking itself by sliding off the bend of the hook. Sometimes also called the “gap”, the “gape” of the hook is the distance between the point of the hook and the shank.
Hook Wire Material
Hooks of today are mainly made of high carbon steel or stainless steel although some manufacturers do incorporate the use of other high-grade, composite steels such as VMC’s Vanadium®. Steel with higher carbon content is much stronger and harder. On its own, stainless steel has better corrosion resistance compared to high carbon steel but is generally more expensive. As such, they do not require further coating after being polished. To shield against corrosion, high carbon hooks are coated or plated in various finishes according to application.
In fact, some plated high carbon hooks such as those plated with tin do boast excellent corrosion resistance in saltwater. Some saltwater anglers prefer to use lightly coated high carbon hooks over stainless steel hooks as these can corrode away over time should a fish escape with a hook embedded in its mouth or throat. Recognizing the strengths and limitations of using high-carbon steel to form the wire of the hook, most manufacturers incorporate sophisticated tempering processes to maintain a balance of hardness and flexibility. High carbon hooks that are too hard can be brittle and break if pressure is placed beyond its tolerances while hooks that are too soft can straighten under similar conditions.
To further reinforce their strength and resistance at the bend, some hooks go through the process of forging which involves slightly flattening the tubular steel wire on opposing sides by compression. Forged hooks are better able to resist bending on a straight pull.
Platings & Coatings
To overcome the corrosive nature of high-carbon hooks, manufacturers apply a range of coatings over the hooks to match specific fishing applications in freshwater and saltwater. Bronze, tin and nickel are the common finishes used although some manufacturers add on colour varnishes or lacquers of red, blue or other interesting colours for specific applications to attract more bites from fish.
Bronze is a basic finish used for hooks as it is most economical but has a low tolerance to corrosion. Gold-coloured hooks are aesthetically pleasing and attractive to fish due to its shine, as in the case of most Sabiki rig hooks. Gold finishing is applied either by plating 24k gold or applying less expensive, lower quality materials over steel wire. Nickel plating is another widely used finish and gives hooks their silver shimmer. While these finishes offer some form of basic protection from corrosion, they are not able to withstand prolonged use in saltwater and are therefore recommended for freshwater fishing.
Black nickel is one notch up the corrosion resistance ladder and is one the most popular platings for hooks. This plating gives hooks their shiny, black colour. Tin-plating is a cost-effective method of protecting high-carbon steel hooks meant for saltwater use as they have a high level of resistance to corrosion. Some key market players such as Mustad and VMC have developed their own anti-corrosion finishes in the pursuit of the ultimate saltwater hook as seen in the former’s Z-Steel coating and VMC’s Permasteel. Both these finishes boast exceptional resilience to corrosion in saltwater.
Hook Size – What’s With The Zeros?
Hook sizes are generally determined by the width of the gap and are designated by a unique numbering system. Hook sizes with a number followed by zero increase in relation to size while hook sizes without a zero decrease in size as the number increases. For example, a size 2/0 hook is larger than a size 1/0 hook while a size 1 hook will be larger than a size 2 hook. However, certain Japanese hooks do not adopt the “zero” designation but have small to large sizes defined relative to ascending numbers. Interestingly, there is no standardization in hook sizes across manufacturers although they may adopt the same sizing convention. A size 2/0 VMC hook may not be exactly the same size as a Mustad 2/0 hook.
Hook Strength – the ‘X’ Factor
You may have come across some hooks, particularly trebles, with markings such as ‘2X’ or ‘3X Strong’ and beyond. These markings are an indication of hook wire thickness. The higher the “X” number, the stronger the hook wire is. The “X” number denotes the shift in sizes in relation to the wire thickness of an equivalent standard hook while other dimensions remain unchanged. Therefore, a ‘1X Strong’ treble hook has the same wire thickness as its standard equivalent one size bigger and a ‘2X Strong’ treble hook has the same wire thickness as its standard equivalent two sizes bigger. For example, a ‘2X Strong’ size 3/0 hook has a wire thickness and strength equivalent of a standard 5/0 hook. Likewise, a ‘3X Strong’ size 3/0 hook has a wire thickness and strength of a standard 6/0 hook. However, like hook sizing, there is no standard classification for strength across manufacturers and as such, is a rather relative indication.
“What’s the Point?”
The point is the critical part of the hook where steel meets tissue upon penetration. Straight, conical, curved, knife or kirbed points are common designs seen in hooks although different manufacturers will also have incorporated proprietary designs with certain characteristics to optimize penetration. VMC’s Spark Point range is an example of such proprietary technology aimed at producing a point that is extremely sharp, rigid and optimized for fast and efficient penetration. To obtain their unique points, hook wires can be shaped by cutting the wire to desired angles, compressing the tip to form the point or grinding the tip. The cutting process produces a sharp point but because some metal is removed, it is not as strong compared to a compressed point. Compressed points are stronger since no metal is removed in the process. While the grinding process creates a sharp point, it also removes some metal, which results in a weaker point that is prone to bend or roll over. Some manufacturers incorporate chemical sharpening on some of their product lines as an additional step after the mechanical sharpening process. Hooks are dipped into an acid bath where the chemical reacts with the metal to smoothen out any burs on the surface and refines the point. This process results in an exceptionally sharp hook point.
While it is debatable which hook point is better, each design has its own application and is a matter of personal preference and fishing style. Besides point sharpness and cut, a hook’s penetrating efficiency also depends on other factors such as the type of tissue being penetrated and the gauge of the hook wire. Typically, the soft flesh on a Diamond Trevally’s lips is easier to penetrate as compared to a Sailfish’s. Likewise, a thinner gauge hook would have a better penetration than one with a significantly thicker gauge.
Barbed or Barbless?
The barb keeps a hook from being dislodged from the mouth of a hooked fish. This little protrusion is formed by cutting the hook wire to make a ‘chip’. This is a delicate process as cutting the wire too deep can reduce the strength of the hook point whereas cutting the wire too little will result in a barb that is too small and hence, defeat its intended purpose. Proponents of catch and release prefer to flatten or file off the barbs on their hooks to minimize tissue damage when de-hooking a fish for release. Some anglers are of the opinion that barbless hooks result in higher chances of fish throwing the hook. While this may be arguable, maintaining a tight line while fighting a fish can drastically reduce such occurrences as any slack in the line can give the fish an opportunity to shake off the hook with ease.
It is amazing how the fishing hook has evolved and been refined throughout the ages into its current form today. I believe the evolution of hooks will not stop here. Driven by the demand for stronger, sharper hooks and increasing awareness of conservation, we can only expect to see more advancement in the years to come as newer technologies and materials are discovered and employed by industry players. Of course being anglers, we can only hope that the introduction of these new technologies and materials would not be at the expense of burning our pockets!